* [PATCH] phy: qcom-qmp: add support for voltage and pre emphesis swing
@ 2021-08-24 23:29 Kuogee Hsieh
2021-08-25 17:49 ` Stephen Boyd
2021-08-25 20:57 ` Bjorn Andersson
0 siblings, 2 replies; 4+ messages in thread
From: Kuogee Hsieh @ 2021-08-24 23:29 UTC (permalink / raw)
To: robdclark, sean, swboyd, vkoul, agross, bjorn.andersson, robh+dt,
devicetree
Cc: abhinavk, aravindh, khsieh, freedreno, linux-arm-msm,
linux-kernel, kishon, p.zabel
Add voltage and pre emphesis swing tables so that voltage and
pre emphsis swing level can be configured base on link rate.
Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org>
---
drivers/phy/qualcomm/phy-qcom-qmp.c | 95 ++++++++++++++++++++++++++++++++-----
1 file changed, 82 insertions(+), 13 deletions(-)
diff --git a/drivers/phy/qualcomm/phy-qcom-qmp.c b/drivers/phy/qualcomm/phy-qcom-qmp.c
index 31036aa..52bab6e 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp.c
@@ -1916,7 +1916,7 @@ static const struct qmp_phy_init_tbl qmp_v4_dp_tx_tbl[] = {
QMP_PHY_INIT_CFG(QSERDES_V4_TX_RES_CODE_LANE_OFFSET_RX, 0x11),
QMP_PHY_INIT_CFG(QSERDES_V4_TX_TX_BAND, 0x4),
QMP_PHY_INIT_CFG(QSERDES_V4_TX_TX_POL_INV, 0x0a),
- QMP_PHY_INIT_CFG(QSERDES_V4_TX_TX_DRV_LVL, 0x2a),
+ QMP_PHY_INIT_CFG(QSERDES_V4_TX_TX_DRV_LVL, 0x22),
QMP_PHY_INIT_CFG(QSERDES_V4_TX_TX_EMP_POST1_LVL, 0x20),
};
@@ -3727,6 +3727,81 @@ static int qcom_qmp_v3_dp_phy_calibrate(struct qmp_phy *qphy)
return 0;
}
+/*
+ * 0x20 deducted from tables
+ *
+ * swing_value |= DP_PHY_TXn_TX_DRV_LVL_MUX_EN;
+ * pre_emphasis_value |= DP_PHY_TXn_TX_EMP_POST1_LVL_MUX_EN;
+*/
+static const u8 qmp_dp_v4_pre_emphasis_hbr3_hbr2[4][4] = {
+ /* p0 p1 p2 p3 */
+ { 0x00, 0x0c, 0x15, 0x1b }, /* s0 */
+ { 0x02, 0x0e, 0x16, 0xff }, /* s1 */
+ { 0x02, 0x11, 0xff, 0xff }, /* s2 */
+ { 0x04, 0xff, 0xff, 0xff } /* s3 */
+};
+
+static const u8 qmp_dp_v4_voltage_swing_hbr3_hbr2[4][4] = {
+ /* p0 p1 p2 p3 */
+ { 0x02, 0x12, 0x16, 0x1a }, /* s0 */
+ { 0x09, 0x19, 0x1f, 0xff }, /* s1 */
+ { 0x10, 0x1f, 0xff, 0xff }, /* s2 */
+ { 0x1f, 0xff, 0xff, 0xff } /* s3 */
+};
+
+static const u8 qmp_dp_v4_pre_emphasis_hbr_rbr[4][4] = {
+ /* p0 p1 p2 p3 */
+ { 0x00, 0x0e, 0x15, 0x1b }, /* s0 */
+ { 0x00, 0x0e, 0x15, 0xff }, /* s1 */
+ { 0x00, 0x0e, 0xff, 0xff }, /* s2 */
+ { 0x04, 0xff, 0xff, 0xff } /* s3 */
+};
+
+static const u8 qmp_dp_v4_voltage_swing_hbr_rbr[4][4] = {
+ /* p0 p1 p2 p3 */
+ { 0x08, 0x0f, 0x16, 0x1f }, /* s0 */
+ { 0x11, 0x1e, 0x1f, 0xff }, /* s1 */
+ { 0x16, 0x1f, 0xff, 0xff }, /* s2 */
+ { 0x1f, 0xff, 0xff, 0xff } /* s3 */
+};
+
+static int qcom_qmp_v4_phy_configure_dp_swing(struct qmp_phy *qphy,
+ unsigned int drv_lvl_reg, unsigned int emp_post_reg)
+{
+ const struct phy_configure_opts_dp *dp_opts = &qphy->dp_opts;
+ unsigned int v_level = 0, p_level = 0;
+ u8 voltage_swing_cfg, pre_emphasis_cfg;
+ int i;
+
+ for (i = 0; i < dp_opts->lanes; i++) {
+ v_level = max(v_level, dp_opts->voltage[i]);
+ p_level = max(p_level, dp_opts->pre[i]);
+ }
+
+
+ if (dp_opts->link_rate <= 2700) {
+ voltage_swing_cfg = qmp_dp_v4_voltage_swing_hbr_rbr[v_level][p_level];
+ pre_emphasis_cfg = qmp_dp_v4_pre_emphasis_hbr_rbr[v_level][p_level];
+ } else {
+ voltage_swing_cfg = qmp_dp_v4_voltage_swing_hbr3_hbr2[v_level][p_level];
+ pre_emphasis_cfg = qmp_dp_v4_pre_emphasis_hbr3_hbr2[v_level][p_level];
+ }
+
+ /* TODO: Move check to config check */
+ if (voltage_swing_cfg == 0xFF && pre_emphasis_cfg == 0xFF)
+ return -EINVAL;
+
+ /* Enable MUX to use Cursor values from these registers */
+ voltage_swing_cfg |= DP_PHY_TXn_TX_DRV_LVL_MUX_EN;
+ pre_emphasis_cfg |= DP_PHY_TXn_TX_EMP_POST1_LVL_MUX_EN;
+
+ writel(voltage_swing_cfg, qphy->tx + drv_lvl_reg);
+ writel(pre_emphasis_cfg, qphy->tx + emp_post_reg);
+ writel(voltage_swing_cfg, qphy->tx2 + drv_lvl_reg);
+ writel(pre_emphasis_cfg, qphy->tx2 + emp_post_reg);
+
+ return 0;
+}
static void qcom_qmp_v4_phy_dp_aux_init(struct qmp_phy *qphy)
{
@@ -3757,14 +3832,7 @@ static void qcom_qmp_v4_phy_dp_aux_init(struct qmp_phy *qphy)
static void qcom_qmp_v4_phy_configure_dp_tx(struct qmp_phy *qphy)
{
- /* Program default values before writing proper values */
- writel(0x27, qphy->tx + QSERDES_V4_TX_TX_DRV_LVL);
- writel(0x27, qphy->tx2 + QSERDES_V4_TX_TX_DRV_LVL);
-
- writel(0x20, qphy->tx + QSERDES_V4_TX_TX_EMP_POST1_LVL);
- writel(0x20, qphy->tx2 + QSERDES_V4_TX_TX_EMP_POST1_LVL);
-
- qcom_qmp_phy_configure_dp_swing(qphy,
+ qcom_qmp_v4_phy_configure_dp_swing(qphy,
QSERDES_V4_TX_TX_DRV_LVL,
QSERDES_V4_TX_TX_EMP_POST1_LVL);
}
@@ -3885,6 +3953,9 @@ static int qcom_qmp_v4_phy_configure_dp_phy(struct qmp_phy *qphy)
writel(drvr1_en, qphy->tx2 + QSERDES_V4_TX_HIGHZ_DRVR_EN);
writel(bias1_en, qphy->tx2 + QSERDES_V4_TX_TRANSCEIVER_BIAS_EN);
+ writel(0x0a, qphy->tx + QSERDES_V4_TX_TX_POL_INV);
+ writel(0x0a, qphy->tx2 + QSERDES_V4_TX_TX_POL_INV);
+
writel(0x18, qphy->pcs + QSERDES_DP_PHY_CFG);
udelay(2000);
writel(0x19, qphy->pcs + QSERDES_DP_PHY_CFG);
@@ -3896,11 +3967,9 @@ static int qcom_qmp_v4_phy_configure_dp_phy(struct qmp_phy *qphy)
10000))
return -ETIMEDOUT;
- writel(0x0a, qphy->tx + QSERDES_V4_TX_TX_POL_INV);
- writel(0x0a, qphy->tx2 + QSERDES_V4_TX_TX_POL_INV);
- writel(0x27, qphy->tx + QSERDES_V4_TX_TX_DRV_LVL);
- writel(0x27, qphy->tx2 + QSERDES_V4_TX_TX_DRV_LVL);
+ writel(0x22, qphy->tx + QSERDES_V4_TX_TX_DRV_LVL);
+ writel(0x22, qphy->tx2 + QSERDES_V4_TX_TX_DRV_LVL);
writel(0x20, qphy->tx + QSERDES_V4_TX_TX_EMP_POST1_LVL);
writel(0x20, qphy->tx2 + QSERDES_V4_TX_TX_EMP_POST1_LVL);
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] phy: qcom-qmp: add support for voltage and pre emphesis swing
2021-08-24 23:29 [PATCH] phy: qcom-qmp: add support for voltage and pre emphesis swing Kuogee Hsieh
@ 2021-08-25 17:49 ` Stephen Boyd
2021-08-27 20:00 ` khsieh
2021-08-25 20:57 ` Bjorn Andersson
1 sibling, 1 reply; 4+ messages in thread
From: Stephen Boyd @ 2021-08-25 17:49 UTC (permalink / raw)
To: Kuogee Hsieh, agross, bjorn.andersson, devicetree, robdclark,
robh+dt, sean, vkoul
Cc: abhinavk, aravindh, freedreno, linux-arm-msm, linux-kernel,
kishon, p.zabel
Quoting Kuogee Hsieh (2021-08-24 16:29:35)
> Add voltage and pre emphesis swing tables so that voltage and
Is it "pre-emphasis"?
> pre emphsis swing level can be configured base on link rate.
This one is also different.
>
> Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org>
Presumably
Fixes: aff188feb5e1 ("phy: qcom-qmp: add support for sm8250-usb3-dp phy")
> ---
> drivers/phy/qualcomm/phy-qcom-qmp.c | 95 ++++++++++++++++++++++++++++++++-----
> 1 file changed, 82 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp.c b/drivers/phy/qualcomm/phy-qcom-qmp.c
> index 31036aa..52bab6e 100644
> --- a/drivers/phy/qualcomm/phy-qcom-qmp.c
> +++ b/drivers/phy/qualcomm/phy-qcom-qmp.c
> @@ -1916,7 +1916,7 @@ static const struct qmp_phy_init_tbl qmp_v4_dp_tx_tbl[] = {
> QMP_PHY_INIT_CFG(QSERDES_V4_TX_RES_CODE_LANE_OFFSET_RX, 0x11),
> QMP_PHY_INIT_CFG(QSERDES_V4_TX_TX_BAND, 0x4),
> QMP_PHY_INIT_CFG(QSERDES_V4_TX_TX_POL_INV, 0x0a),
> - QMP_PHY_INIT_CFG(QSERDES_V4_TX_TX_DRV_LVL, 0x2a),
> + QMP_PHY_INIT_CFG(QSERDES_V4_TX_TX_DRV_LVL, 0x22),
Is 0x22 the better "default"? Can that be described in the commit text?
> QMP_PHY_INIT_CFG(QSERDES_V4_TX_TX_EMP_POST1_LVL, 0x20),
> };
>
> @@ -3727,6 +3727,81 @@ static int qcom_qmp_v3_dp_phy_calibrate(struct qmp_phy *qphy)
>
> return 0;
> }
Nitpick: Newline here please.
> +/*
> + * 0x20 deducted from tables
> + *
> + * swing_value |= DP_PHY_TXn_TX_DRV_LVL_MUX_EN;
> + * pre_emphasis_value |= DP_PHY_TXn_TX_EMP_POST1_LVL_MUX_EN;
> +*/
> +static const u8 qmp_dp_v4_pre_emphasis_hbr3_hbr2[4][4] = {
> + /* p0 p1 p2 p3 */
> + { 0x00, 0x0c, 0x15, 0x1b }, /* s0 */
> + { 0x02, 0x0e, 0x16, 0xff }, /* s1 */
> + { 0x02, 0x11, 0xff, 0xff }, /* s2 */
> + { 0x04, 0xff, 0xff, 0xff } /* s3 */
> +};
> +
> +static const u8 qmp_dp_v4_voltage_swing_hbr3_hbr2[4][4] = {
This looks the same as qmp_dp_v3_voltage_swing_hbr3_hbr2. Can that be
used?
> + /* p0 p1 p2 p3 */
> + { 0x02, 0x12, 0x16, 0x1a }, /* s0 */
> + { 0x09, 0x19, 0x1f, 0xff }, /* s1 */
> + { 0x10, 0x1f, 0xff, 0xff }, /* s2 */
> + { 0x1f, 0xff, 0xff, 0xff } /* s3 */
> +};
> +
> +static const u8 qmp_dp_v4_pre_emphasis_hbr_rbr[4][4] = {
> + /* p0 p1 p2 p3 */
> + { 0x00, 0x0e, 0x15, 0x1b }, /* s0 */
> + { 0x00, 0x0e, 0x15, 0xff }, /* s1 */
> + { 0x00, 0x0e, 0xff, 0xff }, /* s2 */
> + { 0x04, 0xff, 0xff, 0xff } /* s3 */
> +};
> +
> +static const u8 qmp_dp_v4_voltage_swing_hbr_rbr[4][4] = {
> + /* p0 p1 p2 p3 */
> + { 0x08, 0x0f, 0x16, 0x1f }, /* s0 */
> + { 0x11, 0x1e, 0x1f, 0xff }, /* s1 */
> + { 0x16, 0x1f, 0xff, 0xff }, /* s2 */
> + { 0x1f, 0xff, 0xff, 0xff } /* s3 */
Do these comments add any value? Can we drop them?
> +};
> +
> +static int qcom_qmp_v4_phy_configure_dp_swing(struct qmp_phy *qphy,
> + unsigned int drv_lvl_reg, unsigned int emp_post_reg)
> +{
> + const struct phy_configure_opts_dp *dp_opts = &qphy->dp_opts;
> + unsigned int v_level = 0, p_level = 0;
> + u8 voltage_swing_cfg, pre_emphasis_cfg;
> + int i;
> +
> + for (i = 0; i < dp_opts->lanes; i++) {
> + v_level = max(v_level, dp_opts->voltage[i]);
> + p_level = max(p_level, dp_opts->pre[i]);
> + }
> +
> +
Nitpick: Drop extra newline.
> + if (dp_opts->link_rate <= 2700) {
> + voltage_swing_cfg = qmp_dp_v4_voltage_swing_hbr_rbr[v_level][p_level];
> + pre_emphasis_cfg = qmp_dp_v4_pre_emphasis_hbr_rbr[v_level][p_level];
> + } else {
> + voltage_swing_cfg = qmp_dp_v4_voltage_swing_hbr3_hbr2[v_level][p_level];
> + pre_emphasis_cfg = qmp_dp_v4_pre_emphasis_hbr3_hbr2[v_level][p_level];
> + }
> +
> + /* TODO: Move check to config check */
> + if (voltage_swing_cfg == 0xFF && pre_emphasis_cfg == 0xFF)
> + return -EINVAL;
> +
> + /* Enable MUX to use Cursor values from these registers */
> + voltage_swing_cfg |= DP_PHY_TXn_TX_DRV_LVL_MUX_EN;
> + pre_emphasis_cfg |= DP_PHY_TXn_TX_EMP_POST1_LVL_MUX_EN;
> +
> + writel(voltage_swing_cfg, qphy->tx + drv_lvl_reg);
> + writel(pre_emphasis_cfg, qphy->tx + emp_post_reg);
> + writel(voltage_swing_cfg, qphy->tx2 + drv_lvl_reg);
> + writel(pre_emphasis_cfg, qphy->tx2 + emp_post_reg);
This is copy/pasted from qcom_qmp_phy_configure_dp_swing() right? How
about making a function
static int
__qcom_qmp_phy_configure_dp_swing(struct qmp_phy *qphy,
unsigned int drv_lvl_reg,
unsigned int emp_post_reg,
const u8 **voltage_rbr_hbr,
const u8 **pre_emphasis_rbr_hbr,
const u8 **voltage_hbr3_hbr2,
const u8 **pre_emphasis_hbr3_hbr2)
that does the same stuff but allows the tables to be different.
> +
> + return 0;
> +}
>
> static void qcom_qmp_v4_phy_dp_aux_init(struct qmp_phy *qphy)
> {
> @@ -3757,14 +3832,7 @@ static void qcom_qmp_v4_phy_dp_aux_init(struct qmp_phy *qphy)
>
> static void qcom_qmp_v4_phy_configure_dp_tx(struct qmp_phy *qphy)
> {
> - /* Program default values before writing proper values */
> - writel(0x27, qphy->tx + QSERDES_V4_TX_TX_DRV_LVL);
> - writel(0x27, qphy->tx2 + QSERDES_V4_TX_TX_DRV_LVL);
> -
> - writel(0x20, qphy->tx + QSERDES_V4_TX_TX_EMP_POST1_LVL);
> - writel(0x20, qphy->tx2 + QSERDES_V4_TX_TX_EMP_POST1_LVL);
> -
> - qcom_qmp_phy_configure_dp_swing(qphy,
> + qcom_qmp_v4_phy_configure_dp_swing(qphy,
> QSERDES_V4_TX_TX_DRV_LVL,
> QSERDES_V4_TX_TX_EMP_POST1_LVL);
> }
> @@ -3885,6 +3953,9 @@ static int qcom_qmp_v4_phy_configure_dp_phy(struct qmp_phy *qphy)
> writel(drvr1_en, qphy->tx2 + QSERDES_V4_TX_HIGHZ_DRVR_EN);
> writel(bias1_en, qphy->tx2 + QSERDES_V4_TX_TRANSCEIVER_BIAS_EN);
>
> + writel(0x0a, qphy->tx + QSERDES_V4_TX_TX_POL_INV);
> + writel(0x0a, qphy->tx2 + QSERDES_V4_TX_TX_POL_INV);
Is this mentioned in the commit text? Is this fixing the sequence?
It doesn't look like we're adding tables.
> +
> writel(0x18, qphy->pcs + QSERDES_DP_PHY_CFG);
> udelay(2000);
> writel(0x19, qphy->pcs + QSERDES_DP_PHY_CFG);
> @@ -3896,11 +3967,9 @@ static int qcom_qmp_v4_phy_configure_dp_phy(struct qmp_phy *qphy)
> 10000))
> return -ETIMEDOUT;
>
> - writel(0x0a, qphy->tx + QSERDES_V4_TX_TX_POL_INV);
> - writel(0x0a, qphy->tx2 + QSERDES_V4_TX_TX_POL_INV);
>
> - writel(0x27, qphy->tx + QSERDES_V4_TX_TX_DRV_LVL);
> - writel(0x27, qphy->tx2 + QSERDES_V4_TX_TX_DRV_LVL);
> + writel(0x22, qphy->tx + QSERDES_V4_TX_TX_DRV_LVL);
> + writel(0x22, qphy->tx2 + QSERDES_V4_TX_TX_DRV_LVL);
>
> writel(0x20, qphy->tx + QSERDES_V4_TX_TX_EMP_POST1_LVL);
> writel(0x20, qphy->tx2 + QSERDES_V4_TX_TX_EMP_POST1_LVL);
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] phy: qcom-qmp: add support for voltage and pre emphesis swing
2021-08-25 17:49 ` Stephen Boyd
@ 2021-08-27 20:00 ` khsieh
0 siblings, 0 replies; 4+ messages in thread
From: khsieh @ 2021-08-27 20:00 UTC (permalink / raw)
To: Stephen Boyd
Cc: agross, bjorn.andersson, devicetree, robdclark, robh+dt, sean,
vkoul, abhinavk, aravindh, freedreno, linux-arm-msm,
linux-kernel, kishon, p.zabel
On 2021-08-25 10:49, Stephen Boyd wrote:
> Quoting Kuogee Hsieh (2021-08-24 16:29:35)
>> Add voltage and pre emphesis swing tables so that voltage and
>
> Is it "pre-emphasis"?
>
>> pre emphsis swing level can be configured base on link rate.
>
> This one is also different.
>
>>
>> Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org>
>
> Presumably
>
> Fixes: aff188feb5e1 ("phy: qcom-qmp: add support for sm8250-usb3-dp
> phy")
>
>> ---
>> drivers/phy/qualcomm/phy-qcom-qmp.c | 95
>> ++++++++++++++++++++++++++++++++-----
>> 1 file changed, 82 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp.c
>> b/drivers/phy/qualcomm/phy-qcom-qmp.c
>> index 31036aa..52bab6e 100644
>> --- a/drivers/phy/qualcomm/phy-qcom-qmp.c
>> +++ b/drivers/phy/qualcomm/phy-qcom-qmp.c
>> @@ -1916,7 +1916,7 @@ static const struct qmp_phy_init_tbl
>> qmp_v4_dp_tx_tbl[] = {
>> QMP_PHY_INIT_CFG(QSERDES_V4_TX_RES_CODE_LANE_OFFSET_RX, 0x11),
>> QMP_PHY_INIT_CFG(QSERDES_V4_TX_TX_BAND, 0x4),
>> QMP_PHY_INIT_CFG(QSERDES_V4_TX_TX_POL_INV, 0x0a),
>> - QMP_PHY_INIT_CFG(QSERDES_V4_TX_TX_DRV_LVL, 0x2a),
>> + QMP_PHY_INIT_CFG(QSERDES_V4_TX_TX_DRV_LVL, 0x22),
>
> Is 0x22 the better "default"? Can that be described in the commit text?
>
>> QMP_PHY_INIT_CFG(QSERDES_V4_TX_TX_EMP_POST1_LVL, 0x20),
>> };
>>
>> @@ -3727,6 +3727,81 @@ static int qcom_qmp_v3_dp_phy_calibrate(struct
>> qmp_phy *qphy)
>>
>> return 0;
>> }
>
> Nitpick: Newline here please.
>
>> +/*
>> + * 0x20 deducted from tables
>> + *
>> + * swing_value |= DP_PHY_TXn_TX_DRV_LVL_MUX_EN;
>> + * pre_emphasis_value |= DP_PHY_TXn_TX_EMP_POST1_LVL_MUX_EN;
>> +*/
>> +static const u8 qmp_dp_v4_pre_emphasis_hbr3_hbr2[4][4] = {
>> + /* p0 p1 p2 p3 */
>> + { 0x00, 0x0c, 0x15, 0x1b }, /* s0 */
>> + { 0x02, 0x0e, 0x16, 0xff }, /* s1 */
>> + { 0x02, 0x11, 0xff, 0xff }, /* s2 */
>> + { 0x04, 0xff, 0xff, 0xff } /* s3 */
>> +};
>> +
>> +static const u8 qmp_dp_v4_voltage_swing_hbr3_hbr2[4][4] = {
>
> This looks the same as qmp_dp_v3_voltage_swing_hbr3_hbr2. Can that be
> used?
to avoid confuse, i like to keep them separated.
>
>> + /* p0 p1 p2 p3 */
>> + { 0x02, 0x12, 0x16, 0x1a }, /* s0 */
>> + { 0x09, 0x19, 0x1f, 0xff }, /* s1 */
>> + { 0x10, 0x1f, 0xff, 0xff }, /* s2 */
>> + { 0x1f, 0xff, 0xff, 0xff } /* s3 */
>> +};
>> +
>> +static const u8 qmp_dp_v4_pre_emphasis_hbr_rbr[4][4] = {
>> + /* p0 p1 p2 p3 */
>> + { 0x00, 0x0e, 0x15, 0x1b }, /* s0 */
>> + { 0x00, 0x0e, 0x15, 0xff }, /* s1 */
>> + { 0x00, 0x0e, 0xff, 0xff }, /* s2 */
>> + { 0x04, 0xff, 0xff, 0xff } /* s3 */
>> +};
>> +
>> +static const u8 qmp_dp_v4_voltage_swing_hbr_rbr[4][4] = {
>> + /* p0 p1 p2 p3 */
>> + { 0x08, 0x0f, 0x16, 0x1f }, /* s0 */
>> + { 0x11, 0x1e, 0x1f, 0xff }, /* s1 */
>> + { 0x16, 0x1f, 0xff, 0xff }, /* s2 */
>> + { 0x1f, 0xff, 0xff, 0xff } /* s3 */
>
> Do these comments add any value? Can we drop them?
>
>> +};
>> +
>> +static int qcom_qmp_v4_phy_configure_dp_swing(struct qmp_phy *qphy,
>> + unsigned int drv_lvl_reg, unsigned int emp_post_reg)
>> +{
>> + const struct phy_configure_opts_dp *dp_opts = &qphy->dp_opts;
>> + unsigned int v_level = 0, p_level = 0;
>> + u8 voltage_swing_cfg, pre_emphasis_cfg;
>> + int i;
>> +
>> + for (i = 0; i < dp_opts->lanes; i++) {
>> + v_level = max(v_level, dp_opts->voltage[i]);
>> + p_level = max(p_level, dp_opts->pre[i]);
>> + }
>> +
>> +
>
> Nitpick: Drop extra newline.
>
>> + if (dp_opts->link_rate <= 2700) {
>> + voltage_swing_cfg =
>> qmp_dp_v4_voltage_swing_hbr_rbr[v_level][p_level];
>> + pre_emphasis_cfg =
>> qmp_dp_v4_pre_emphasis_hbr_rbr[v_level][p_level];
>> + } else {
>> + voltage_swing_cfg =
>> qmp_dp_v4_voltage_swing_hbr3_hbr2[v_level][p_level];
>> + pre_emphasis_cfg =
>> qmp_dp_v4_pre_emphasis_hbr3_hbr2[v_level][p_level];
>> + }
>> +
>> + /* TODO: Move check to config check */
>> + if (voltage_swing_cfg == 0xFF && pre_emphasis_cfg == 0xFF)
>> + return -EINVAL;
>> +
>> + /* Enable MUX to use Cursor values from these registers */
>> + voltage_swing_cfg |= DP_PHY_TXn_TX_DRV_LVL_MUX_EN;
>> + pre_emphasis_cfg |= DP_PHY_TXn_TX_EMP_POST1_LVL_MUX_EN;
>> +
>> + writel(voltage_swing_cfg, qphy->tx + drv_lvl_reg);
>> + writel(pre_emphasis_cfg, qphy->tx + emp_post_reg);
>> + writel(voltage_swing_cfg, qphy->tx2 + drv_lvl_reg);
>> + writel(pre_emphasis_cfg, qphy->tx2 + emp_post_reg);
>
> This is copy/pasted from qcom_qmp_phy_configure_dp_swing() right? How
> about making a function
>
> static int
> __qcom_qmp_phy_configure_dp_swing(struct qmp_phy *qphy,
> unsigned int drv_lvl_reg,
> unsigned int emp_post_reg,
> const u8 **voltage_rbr_hbr,
> const u8 **pre_emphasis_rbr_hbr,
> const u8 **voltage_hbr3_hbr2,
> const u8 **pre_emphasis_hbr3_hbr2)
>
> that does the same stuff but allows the tables to be different.
>
>> +
>> + return 0;
>> +}
>>
>> static void qcom_qmp_v4_phy_dp_aux_init(struct qmp_phy *qphy)
>> {
>> @@ -3757,14 +3832,7 @@ static void qcom_qmp_v4_phy_dp_aux_init(struct
>> qmp_phy *qphy)
>>
>> static void qcom_qmp_v4_phy_configure_dp_tx(struct qmp_phy *qphy)
>> {
>> - /* Program default values before writing proper values */
>> - writel(0x27, qphy->tx + QSERDES_V4_TX_TX_DRV_LVL);
>> - writel(0x27, qphy->tx2 + QSERDES_V4_TX_TX_DRV_LVL);
>> -
>> - writel(0x20, qphy->tx + QSERDES_V4_TX_TX_EMP_POST1_LVL);
>> - writel(0x20, qphy->tx2 + QSERDES_V4_TX_TX_EMP_POST1_LVL);
>> -
>> - qcom_qmp_phy_configure_dp_swing(qphy,
>> + qcom_qmp_v4_phy_configure_dp_swing(qphy,
>> QSERDES_V4_TX_TX_DRV_LVL,
>> QSERDES_V4_TX_TX_EMP_POST1_LVL);
>> }
>> @@ -3885,6 +3953,9 @@ static int
>> qcom_qmp_v4_phy_configure_dp_phy(struct qmp_phy *qphy)
>> writel(drvr1_en, qphy->tx2 + QSERDES_V4_TX_HIGHZ_DRVR_EN);
>> writel(bias1_en, qphy->tx2 +
>> QSERDES_V4_TX_TRANSCEIVER_BIAS_EN);
>>
>> + writel(0x0a, qphy->tx + QSERDES_V4_TX_TX_POL_INV);
>> + writel(0x0a, qphy->tx2 + QSERDES_V4_TX_TX_POL_INV);
>
> Is this mentioned in the commit text? Is this fixing the sequence?
> It doesn't look like we're adding tables.
add these since they are missed from HPG sequence.
>
>> +
>> writel(0x18, qphy->pcs + QSERDES_DP_PHY_CFG);
>> udelay(2000);
>> writel(0x19, qphy->pcs + QSERDES_DP_PHY_CFG);
>> @@ -3896,11 +3967,9 @@ static int
>> qcom_qmp_v4_phy_configure_dp_phy(struct qmp_phy *qphy)
>> 10000))
>> return -ETIMEDOUT;
>>
>> - writel(0x0a, qphy->tx + QSERDES_V4_TX_TX_POL_INV);
>> - writel(0x0a, qphy->tx2 + QSERDES_V4_TX_TX_POL_INV);
>>
>> - writel(0x27, qphy->tx + QSERDES_V4_TX_TX_DRV_LVL);
>> - writel(0x27, qphy->tx2 + QSERDES_V4_TX_TX_DRV_LVL);
>> + writel(0x22, qphy->tx + QSERDES_V4_TX_TX_DRV_LVL);
>> + writel(0x22, qphy->tx2 + QSERDES_V4_TX_TX_DRV_LVL);
>>
>> writel(0x20, qphy->tx + QSERDES_V4_TX_TX_EMP_POST1_LVL);
>> writel(0x20, qphy->tx2 + QSERDES_V4_TX_TX_EMP_POST1_LVL);
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] phy: qcom-qmp: add support for voltage and pre emphesis swing
2021-08-24 23:29 [PATCH] phy: qcom-qmp: add support for voltage and pre emphesis swing Kuogee Hsieh
2021-08-25 17:49 ` Stephen Boyd
@ 2021-08-25 20:57 ` Bjorn Andersson
1 sibling, 0 replies; 4+ messages in thread
From: Bjorn Andersson @ 2021-08-25 20:57 UTC (permalink / raw)
To: Kuogee Hsieh
Cc: robdclark, sean, swboyd, vkoul, agross, robh+dt, devicetree,
abhinavk, aravindh, freedreno, linux-arm-msm, linux-kernel,
kishon, p.zabel
On Tue 24 Aug 16:29 PDT 2021, Kuogee Hsieh wrote:
> Add voltage and pre emphesis swing tables so that voltage and
> pre emphsis swing level can be configured base on link rate.
>
I think it would be nice if $subject, or at least the commit message
mentioned that this relates to the DisplayPort part of the QMP driver.
Also the commit message states that this allows someone/something to
configure the properties based on link rate. But it doesn't state why
this is needed.
> Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org>
> ---
> drivers/phy/qualcomm/phy-qcom-qmp.c | 95 ++++++++++++++++++++++++++++++++-----
> 1 file changed, 82 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp.c b/drivers/phy/qualcomm/phy-qcom-qmp.c
> index 31036aa..52bab6e 100644
> --- a/drivers/phy/qualcomm/phy-qcom-qmp.c
> +++ b/drivers/phy/qualcomm/phy-qcom-qmp.c
> @@ -1916,7 +1916,7 @@ static const struct qmp_phy_init_tbl qmp_v4_dp_tx_tbl[] = {
> QMP_PHY_INIT_CFG(QSERDES_V4_TX_RES_CODE_LANE_OFFSET_RX, 0x11),
> QMP_PHY_INIT_CFG(QSERDES_V4_TX_TX_BAND, 0x4),
> QMP_PHY_INIT_CFG(QSERDES_V4_TX_TX_POL_INV, 0x0a),
> - QMP_PHY_INIT_CFG(QSERDES_V4_TX_TX_DRV_LVL, 0x2a),
> + QMP_PHY_INIT_CFG(QSERDES_V4_TX_TX_DRV_LVL, 0x22),
Why is this initial value changed in order to make the swing and
emphasis configurable?
> QMP_PHY_INIT_CFG(QSERDES_V4_TX_TX_EMP_POST1_LVL, 0x20),
> };
>
> @@ -3727,6 +3727,81 @@ static int qcom_qmp_v3_dp_phy_calibrate(struct qmp_phy *qphy)
>
> return 0;
> }
> +/*
> + * 0x20 deducted from tables
> + *
> + * swing_value |= DP_PHY_TXn_TX_DRV_LVL_MUX_EN;
> + * pre_emphasis_value |= DP_PHY_TXn_TX_EMP_POST1_LVL_MUX_EN;
How about rewriting this as something like
"The values in these tables are given without MUX_EN (0x20) bit set"
?
> +*/
> +static const u8 qmp_dp_v4_pre_emphasis_hbr3_hbr2[4][4] = {
> + /* p0 p1 p2 p3 */
> + { 0x00, 0x0c, 0x15, 0x1b }, /* s0 */
> + { 0x02, 0x0e, 0x16, 0xff }, /* s1 */
> + { 0x02, 0x11, 0xff, 0xff }, /* s2 */
> + { 0x04, 0xff, 0xff, 0xff } /* s3 */
> +};
> +
> +static const u8 qmp_dp_v4_voltage_swing_hbr3_hbr2[4][4] = {
> + /* p0 p1 p2 p3 */
> + { 0x02, 0x12, 0x16, 0x1a }, /* s0 */
> + { 0x09, 0x19, 0x1f, 0xff }, /* s1 */
> + { 0x10, 0x1f, 0xff, 0xff }, /* s2 */
> + { 0x1f, 0xff, 0xff, 0xff } /* s3 */
> +};
> +
> +static const u8 qmp_dp_v4_pre_emphasis_hbr_rbr[4][4] = {
> + /* p0 p1 p2 p3 */
> + { 0x00, 0x0e, 0x15, 0x1b }, /* s0 */
> + { 0x00, 0x0e, 0x15, 0xff }, /* s1 */
> + { 0x00, 0x0e, 0xff, 0xff }, /* s2 */
> + { 0x04, 0xff, 0xff, 0xff } /* s3 */
> +};
> +
> +static const u8 qmp_dp_v4_voltage_swing_hbr_rbr[4][4] = {
> + /* p0 p1 p2 p3 */
> + { 0x08, 0x0f, 0x16, 0x1f }, /* s0 */
> + { 0x11, 0x1e, 0x1f, 0xff }, /* s1 */
> + { 0x16, 0x1f, 0xff, 0xff }, /* s2 */
> + { 0x1f, 0xff, 0xff, 0xff } /* s3 */
> +};
> +
> +static int qcom_qmp_v4_phy_configure_dp_swing(struct qmp_phy *qphy,
> + unsigned int drv_lvl_reg, unsigned int emp_post_reg)
> +{
> + const struct phy_configure_opts_dp *dp_opts = &qphy->dp_opts;
> + unsigned int v_level = 0, p_level = 0;
> + u8 voltage_swing_cfg, pre_emphasis_cfg;
The "_cfg" suffix on these variables doesn't really add any value.
Frankly, calling them "voltage" (or "swing") and "emphasis" seems just
as expressive, but easier to read.
> + int i;
> +
> + for (i = 0; i < dp_opts->lanes; i++) {
> + v_level = max(v_level, dp_opts->voltage[i]);
> + p_level = max(p_level, dp_opts->pre[i]);
> + }
> +
> +
> + if (dp_opts->link_rate <= 2700) {
> + voltage_swing_cfg = qmp_dp_v4_voltage_swing_hbr_rbr[v_level][p_level];
> + pre_emphasis_cfg = qmp_dp_v4_pre_emphasis_hbr_rbr[v_level][p_level];
> + } else {
> + voltage_swing_cfg = qmp_dp_v4_voltage_swing_hbr3_hbr2[v_level][p_level];
> + pre_emphasis_cfg = qmp_dp_v4_pre_emphasis_hbr3_hbr2[v_level][p_level];
> + }
> +
> + /* TODO: Move check to config check */
> + if (voltage_swing_cfg == 0xFF && pre_emphasis_cfg == 0xFF)
Why is this && and not || ?
> + return -EINVAL;
> +
> + /* Enable MUX to use Cursor values from these registers */
> + voltage_swing_cfg |= DP_PHY_TXn_TX_DRV_LVL_MUX_EN;
> + pre_emphasis_cfg |= DP_PHY_TXn_TX_EMP_POST1_LVL_MUX_EN;
> +
> + writel(voltage_swing_cfg, qphy->tx + drv_lvl_reg);
> + writel(pre_emphasis_cfg, qphy->tx + emp_post_reg);
> + writel(voltage_swing_cfg, qphy->tx2 + drv_lvl_reg);
> + writel(pre_emphasis_cfg, qphy->tx2 + emp_post_reg);
> +
This function is called once, so why is drv_lvl_reg and emp_post_reg
variables passed to the function, rather than just using the defines
directly?
Regards,
Bjorn
> + return 0;
> +}
>
> static void qcom_qmp_v4_phy_dp_aux_init(struct qmp_phy *qphy)
> {
> @@ -3757,14 +3832,7 @@ static void qcom_qmp_v4_phy_dp_aux_init(struct qmp_phy *qphy)
>
> static void qcom_qmp_v4_phy_configure_dp_tx(struct qmp_phy *qphy)
> {
> - /* Program default values before writing proper values */
> - writel(0x27, qphy->tx + QSERDES_V4_TX_TX_DRV_LVL);
> - writel(0x27, qphy->tx2 + QSERDES_V4_TX_TX_DRV_LVL);
> -
> - writel(0x20, qphy->tx + QSERDES_V4_TX_TX_EMP_POST1_LVL);
> - writel(0x20, qphy->tx2 + QSERDES_V4_TX_TX_EMP_POST1_LVL);
> -
> - qcom_qmp_phy_configure_dp_swing(qphy,
> + qcom_qmp_v4_phy_configure_dp_swing(qphy,
> QSERDES_V4_TX_TX_DRV_LVL,
> QSERDES_V4_TX_TX_EMP_POST1_LVL);
> }
> @@ -3885,6 +3953,9 @@ static int qcom_qmp_v4_phy_configure_dp_phy(struct qmp_phy *qphy)
> writel(drvr1_en, qphy->tx2 + QSERDES_V4_TX_HIGHZ_DRVR_EN);
> writel(bias1_en, qphy->tx2 + QSERDES_V4_TX_TRANSCEIVER_BIAS_EN);
>
> + writel(0x0a, qphy->tx + QSERDES_V4_TX_TX_POL_INV);
> + writel(0x0a, qphy->tx2 + QSERDES_V4_TX_TX_POL_INV);
> +
> writel(0x18, qphy->pcs + QSERDES_DP_PHY_CFG);
> udelay(2000);
> writel(0x19, qphy->pcs + QSERDES_DP_PHY_CFG);
> @@ -3896,11 +3967,9 @@ static int qcom_qmp_v4_phy_configure_dp_phy(struct qmp_phy *qphy)
> 10000))
> return -ETIMEDOUT;
>
> - writel(0x0a, qphy->tx + QSERDES_V4_TX_TX_POL_INV);
> - writel(0x0a, qphy->tx2 + QSERDES_V4_TX_TX_POL_INV);
>
> - writel(0x27, qphy->tx + QSERDES_V4_TX_TX_DRV_LVL);
> - writel(0x27, qphy->tx2 + QSERDES_V4_TX_TX_DRV_LVL);
> + writel(0x22, qphy->tx + QSERDES_V4_TX_TX_DRV_LVL);
> + writel(0x22, qphy->tx2 + QSERDES_V4_TX_TX_DRV_LVL);
>
> writel(0x20, qphy->tx + QSERDES_V4_TX_TX_EMP_POST1_LVL);
> writel(0x20, qphy->tx2 + QSERDES_V4_TX_TX_EMP_POST1_LVL);
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
>
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-08-27 20:00 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2021-08-24 23:29 [PATCH] phy: qcom-qmp: add support for voltage and pre emphesis swing Kuogee Hsieh
2021-08-25 17:49 ` Stephen Boyd
2021-08-27 20:00 ` khsieh
2021-08-25 20:57 ` Bjorn Andersson
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